If you're an avid Gmail user you know that when you're replying to a long email it's easy for the context to get lost. Blogger John Graham-Cumming points out that, like many other email programs, Gmail has the handy feature where you can select a block of text, hit reply, and only that text is quoted in the response.

Instead of simply hitting reply to an email, select the block of text you're specifically replying to, and then hit reply. Only the block of text you selected is quoted in the reply email, which cuts down on all the junk text you get in long email chains. Most email programs have this built in—and this has been in Gmail for a while—but it's a handy tip nonetheless.